s3-privileges: add handling of both old and new formats in database

We update privileges on a per-record basis instead of all at once, as
this maintains maximum compatibility is someone uses old tools with a
new version of Samba. The also auto-detects the byte order of the old
entries in the database, and copes with either native or reversed byte
order.

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

diff --git a/source3/lib/privileges.c b/source3/lib/privileges.c
index f8ade863df4f009126e1e4996777d37a2e4b2b2f..13d80ca99058ca9198dfb09f9a3856e580e4ea87 100644 (file)
--- a/source3/lib/privileges.c
+++ b/source3/lib/privileges.c
@@ -37,6 +37,35 @@ typedef struct {
        SID_LIST sids;
 } PRIV_SID_LIST;
 
+/*
+  interpret an old style SE_PRIV structure
+ */
+static uint64_t map_old_SE_PRIV(unsigned char *dptr)
+{
+       uint32_t *old_masks = (uint32_t *)dptr;
+       /*
+        * the old privileges code only ever used up to 0x800, except
+        * for a special case of 'SE_ALL_PRIVS' which was 0xFFFFFFFF
+        */
+       if (old_masks[0] == 0xFFFFFFFF) {
+               /* they set all privileges */
+               return SE_ALL_PRIVS;
+       }
+
+       /* the old code used the machine byte order, but we don't know
+        * the byte order of the machine that wrote it. However we can
+        * tell what byte order it was by taking advantage of the fact
+        * that it only ever use up to 0x800
+        */
+       if (dptr[0] || dptr[1]) {
+               /* it was little endian */
+               return IVAL(dptr, 0);
+       }
+
+       /* it was either zero or big-endian */
+       return RIVAL(dptr, 0);
+}
+
 
 static bool get_privileges( const struct dom_sid *sid, uint64_t *mask )
 {
@@ -66,19 +95,18 @@ static bool get_privileges( const struct dom_sid *sid, uint64_t *mask )
        }
 
        if (data.dsize == 4*4) {
-               DEBUG(3, ("get_privileges: Should not have obtained old-style privileges record for SID "
-                         "[%s]\n", sid_string_dbg(sid)));
-               return False;
-       }
+               /* it's an old style SE_PRIV structure. */
+               *mask = map_old_SE_PRIV(data.dptr);
+       } else {
+               if (data.dsize != sizeof( uint64_t ) ) {
+                       DEBUG(3, ("get_privileges: Invalid privileges record assigned to SID "
+                                 "[%s]\n", sid_string_dbg(sid)));
+                       return False;
+               }
 
-       if (data.dsize != sizeof( uint64_t ) ) {
-               DEBUG(3, ("get_privileges: Invalid privileges record assigned to SID "
-                         "[%s]\n", sid_string_dbg(sid)));
-               return False;
+               *mask = BVAL(data.dptr, 0);
        }
 
-       *mask = BVAL(data.dptr, 0);
-
        TALLOC_FREE(data.dptr);
 
        return True;
@@ -113,8 +141,8 @@ static bool set_privileges( const struct dom_sid *sid, uint64_t *mask )
        /* This writes the 64 bit bitmask out in little endian format */
        SBVAL(privbuf,0,*mask);
 
-       data.dptr  = (uint8 *)mask;
-       data.dsize = sizeof(uint64_t);
+       data.dptr  = privbuf;
+       data.dsize = sizeof(privbuf);
 
        return NT_STATUS_IS_OK(dbwrap_store_bystring(db, keystr, data,
                                                     TDB_REPLACE));
@@ -178,11 +206,6 @@ static int priv_traverse_fn(struct db_record *rec, void *state)
        struct dom_sid sid;
        fstring sid_string;
 
-       /* easy check first */
-
-       if (rec->value.dsize != sizeof(uint64_t) )
-               return 0;
-
        /* check we have a PRIV_+SID entry */
 
        if ( strncmp((char *)rec->key.dptr, PRIVPREFIX, prefixlen) != 0)
@@ -196,19 +219,16 @@ static int priv_traverse_fn(struct db_record *rec, void *state)
                uint64_t mask;
 
                if (rec->value.dsize == 4*4) {
-                       DEBUG(3, ("get_privileges: Should not have obtained old-style privileges record for SID "
-                                 "[%s]\n", sid_string));
-                       return 0;
-               }
-
-               if (rec->value.dsize != sizeof( uint64_t ) ) {
-                       DEBUG(3, ("get_privileges: Invalid privileges record assigned to SID "
-                                 "[%s]\n", sid_string));
-                       return 0;
+                       mask = map_old_SE_PRIV(rec->value.dptr);
+               } else {
+                       if (rec->value.dsize != sizeof( uint64_t ) ) {
+                               DEBUG(3, ("get_privileges: Invalid privileges record assigned to SID "
+                                         "[%s]\n", sid_string));
+                               return 0;
+                       }
+                       mask = BVAL(rec->value.dptr, 0);
                }
 
-               mask = BVAL(rec->value.dptr, 0);
-
                /* if the SID does not have the specified privilege
                   then just return */